The function of a VPN (Virtual Private Network) in securing internet connections is to create a secure, encrypted tunnel between the user's device and the internet. This protects the user's online activity from eavesdropping and interception, particularly on public Wi-Fi networks. By masking users' IP addresses, VPNs also enhance privacy and anonymity, making it more difficult for third parties to track online behavior. Additionally, VPNs can bypass geographical restrictions, granting users access to content that might be unavailable in their region.